Elevator switch lock



Feb. 3. 1925.

llmml' "HIWL F. WOLFF ELEVATOR SWI TCH LOCK Filed June 14, 1922 F. WOLFF ELEvAToR swITcH Locx Filed June 14, 1922 2 Sheets-Sheet 2 A. l if A f Patented Feb. 3, 1925.

UNITED STATES PATENT OFFICE.

-FRANZ WoLFF, on sAN rRANoIsodjoALironNIn, AssIcfNony or oNE-HLF .To GEORGE F, Bo'rsCHnrnnn, or SANFRANCISCO, CALIFORNIA.

ELEVATOR SWITCH LOCK.

Application filed June 14, 1922. serial N0. assess.

To @ZZ whom t may concern: t

Be it known that I, FRANZ lVoLFF, a citi- Zen of the United States, residing in the city and county of San Francisco and State l of California, have invented a new and useful Improvement in an Elevator Switch Lock, of which the following is a specification.

My invention relates to improvements in a switch lock for elevators and the like wherein a latch operates to normally lock an elevator door and maintain an electric control circuit in closed condition when the door is closed and to automatically break the control circuit-when the door is opened.

The primary object of my invention is to provide an improved switch lock for elevator doors and the like.

Another Objectis to provide an improved device in which electric circuit closing elements are arranged to be actuated by gravity vto maintain a control circuit closed while an elevator door is closed and to break the circuit while the door is open, to prevent operation of the elevator while said door is open.

Another object is to provide an improved construction arranged to insure the breaking of the'control circuit when the 'door is openedand to eifectively prevent the closing of the circuit until the door is locked in a closed position, thereby insuring against accident due to premature starting of the elevator.

A further object is to provide an improved construction of simple and etlicient construction which may be readily installed for opera-tion' in conjunction with the ordinary" elevator door lock.

Other important objects of my invention are to provide improved insulating means, to render thecontacting and locking elementsfseparatel'y accessible, -and to reduce wear and damage'to the contact elements.

I accomplish -these and other objects by means of the device disclosed in the drawings forming a part of the present specitic'ation wherein like characters of reference are used to designate similar parts throughout said specitication'and drawings, and in which:

` Fig. 1 is a broken front elevation of ya por- 5 5 theretoI Fig. 'Qis a front elevation of my improved switch lock with the outer cover portions removed, the latch being shown in the locking position.

Fig. 3 is a similar view disclosing the latch moved to unlock the door.

Figs. 4 and 5 are sectional views taken upon the lines 4-4 and 5 5 respectively, of Fig. 3 in the directions indicated.

Referring to the drawings the numeral 1 is used to designate in general an elevator door operating within a easement 2, said door being provided with a suitable latch 3 of any standard construction such as is commonly installed upon the door of an elevater.

Upon the upper portion of the door I provide a latch 4 pivotally mounted upon a suitable mounting 6, the rearward end of said latch being connected with the latch 3 by a rod 7 or other rigid connection. The forward portion of the latch 4 is arranged to enter an opening in the proximate side of a switch housing 8 secured upon the casement Q adjacent the latch 4 when the door 1 is closed, said forward portion being notched to form a shoulder 9 adapted to enter into locking engagement with an inwardly disposed extension 10 formed upon the housing adjacent the opening. The latch 4 is normally maintained in locking position as shown in Fig. 2 of the drawings by the weight of the rearward portion of the latch and the connecting rod 7, thereby fastening the door in closed position with additional security and securing against the inadvertent or unauthorized opening of the door.

A stirrup 11 is slidably mounted within the housing 8 upon guides 12 formed upon opposite vsides ofthe housing, said guides being preferably cast as an integral part of the housing. A circuit closing contact 13 is mountedupon the upper end of a post 14 secured inv insulated relation upon the y top of the stirrup, said contact being secured upon a sleeve 16 having a limited slidingr movement upon the post 14 against the pressure of a spring 17 for a purpose hereinafter more fully explained. t

The stirrup 11 is normallyheld by its own Weight in the lower portion of the housing 8. When the forward portion of the latch 4 yenters the housing the point of the latch'enters the stirrup,- a cam surface Ymore fully described, and are connected within the elevator control circuit by 'suit Y able connecting wires 22 entering the housingY through a conduit 23 connected thereto.

The construction of the housing S is of particular importance in my invention in that it may be easily and cheaply manufactured VVand assembled and because itaf-V fords a compact and eilicient means for insulating'the electric contacts, and for theY further reason that it provides ready access to the contacts and operating parts for inspection and repair. The housing consists of a substantial-ly rectangular frame 26 having the side opening and inwardly projecting extension above described in connection Vwith the latch il. Cover portions 27 are secured upon the lower portion of each side of the housing by suitable screws, said por-V tions 27 having the guides 12 above inentioned cast integrally therewith to receive the stirrup 11. Strips 28 of insulating maW terial are insetl into the upper portions ofV f the sides of the frame 26 as shown in Figs.

2 and 8, and a strip 29 of insulating` material secured upon the inner side of the top of the frame 26, the control vcontacts 21 being secured upon the strip 29. p The upper portions of the sides of the housing are closedV by cover portions 31 made of suitable insulating material, the Vlower edge of each portion 31 matching with the adjacent edge ofthe adjacent coverportion 27, forming an insulated chamber within the upper por-V tion of the housing. In this manner the contacts ai'e fully enclosed within dielectric material in such manner as to prevent slierting ofthe circuit should oneof the contacts Ybecome loosened, and likewise insuring against damage due to arcing. rIfhe fact that the upper cover portions 31 of the housing are removable independently fromV the lower portions 27 is of importance because of the ease with which laccess may be had to the contacts without disturbing the stirrupand its related elements. In similar manner the lower cover portion may be removed separately vto obtain access to the stirrup without disturbingV the insulation of the contacts. o

The device operates in the following manner.v When'the point of the latch 4 enters the stirrup and is Vmoved, either by the operator or bythe weight of the rod 7, into the locking position, the stirrup, riding upon: the" cam Y, surface 18, is elevated and contacts which would otherwise result in'v Y The height o f excessive wear and damage.

the cani-surface -18 is so ddesigned that contact willnot be made until after thel shoulderV 9 hasheen moved into locking engagement with the extension 10, in this manner effector before the door is closed and locked. So long as the door remains locked in the closed position the contacts will be held in circuit closing engagement by the weight` ofthe-rod '7 and the elevator may be operated in the usual manner.

When the latch is moved to release the door for opening. the weight of the stirrup Vwill normally operate to break the electric control circuit by lowering the contact 13 out of engagement Ywith the contacts 21. However,y as contacts of the'character described are subject to what is commonly termed freezing and often requires a considerable force to effect a separation, I have provided a lower cam surface 32 upon the forward portion of the latch 4: which is ai'- ranged to engage aA transverse portion 33 of the stirrup Vwhen the latch is moved from the locking position. The cam portion 32 is-'arranged to engage the stirrup before the shoulder '9 disengages the extension 10 as 'shown in dotted lines in Fig. 2 of the drawings, .in this manner insuring that the control circuit be broken prior to the opening of vthe door. As the circuit will now of necessity remain broken until the latch has again been moved to lock the door in closed osition, it will atoiice be seen that anaccident diie to premature starting of the elevator will be eftectually prevented. The portion 33 likewise prevents the stirrup from Vbeing thrown upwardY by the initial impact of the latch 4t against the upper portion 19 thus preventing a premature contact. 'l'

While I have illustrated my improved switch lock in connection with a door of the sliding type, it is to be understood that by a proper arrangement andr disposition ofthe Y housing 'andlatch 4 the device may be ap- Y` pliedto operate in anfidentical.manner in connection with doors of the swinging, folding, or other types commonly installed in elevator construction.

Having thus described my invention what I claim asnew and desire to secureby Let-v ters Patent is: i

1. In a switch'lock for elevators andthe like, a housingcomprising a frame; insulation secured upon the inner side ofthe top broken between said contacts 21.V

tually preventing the starting of the eleva- '280 and the upper portion of the sides of the frame; front and back covers secured upon the frame, said covers each consisting of a lower portion and an upper portion, formed from a plate of dielectric material, sep arately removable from the frame as and for the purposes described.

2. ln a switch lock for elevators and the like, a housing comprising a frame; insulation secured upon the inner side of the top and the upper portion or the sides of the frame; covers removably mounted upon the front and back of the frame, said cover each consisting oi a lower portion having guides i'ormed integrally therewith, and upper portions formed from dielectric material, said upper and lower portions being separately removable; iixed contacts mounted within the insulated upper portion ot the frame; and a movable contact slidably mounted upon the guides within the lower portion of the frame, as and for the purposes described.

3. ln a switch lock for elevators and the like, a housing;` comprising a frame; insulation secured upon the inner side of the top and upper portion of the frame; covers removably secured upon the front and back of the frame, said covers each consisting of a lower portion having guides formed integrally therewith upon the inner sides thereof, and an upper portion formed from dielectric material, said upper and lower portions being separately removable; fixed electric contacts secured within the upper insulated portion of the frame; a stirrup slidably mounted upon the guides within the lower portion of the frame; and a movable cont-act carried by said stirrup as and for the purposes described.

4. A switch lock for elevators and the like comprising a housing consistinv of a frame mounted adjacent an elevator coor; insulation secured upon the inner side of the top and upper portion of the frame; covers removably secured upon the front and back of the frame, said covers each consisting of a lower portion having guides :formed integral therewith upon the inner sides thereof, and an upper portion formed 'from dielectric material said upper and lower portions being separately removable; fixed electric contacts secured within the upper insulated portion ot the frame; a stirrup slidably mounted upon the guides within the lower portion of the frame; a movable Contact carried by said stirrup, and arranged to engage the fixed contacts, said movable contact being' normally held in circuit breakingr position by the weight ot the stirrup; and a latch pivotally mounted upon the door and arranged to enter the housingA to secure the door in closed position, said latch having upper and lower cam surfaces arranged to engage the stirrup to move the stirrup upwardly when the door is closed whereby the movable contact is moved to close a circuit between the fixed contacts, and to move the stirrup downwardly to break said circuit when the door is opened.

In Witness whereof I hereunto set my signature.

FRANZ WOLFF. 

